Optimize lib for large datasets

**Description**
Currently services lacks proper notifications support.

**Proposed solution**
Add configurable notifications with sensible defaults.

**Priority**: Low/Medium

The issue does not name files or tests; start by locating the services implementation and any existing notification or configuration entry points. Clarify the expected notification behavior and sensible defaults, then verify that notifications are configurable and covered by the relevant checks.

Written by the indexing model from the issue text.